Castro Bustelo, VerónicaRodil Rodríguez, María del RosarioQuintana Álvarez, José BenitoCela Torrijos, RafaelSánchez Fernández, LauraGonzález Mariño, Iria2020-01-212021-06-072019-09-27Castro V, Rodil R, Quintana JB, Cela R, Sánchez-Fernández L, González-Mariño I, Determination of human metabolites of chlorinated phosphorous flame retardants in wastewater by N-tert-butyldimethylsilylN-methyltrifluoroacetamide-derivatization and gas chromatography-high resolution mass spectrometry, Journal of Chromatography A (2019), https://doi.org/10.1016/j.chroma.2019.06.0150021-9673http://hdl.handle.net/10347/20586The analysis of wastewater for the determination of human biomarkers of exposure (human metabolites) is a non-intrusive, economic and complementary alternative to the analysis of urine in the monitoring of human exposure to chemicals of concern. This study provides the first gas chromatography-based method for the determination of three metabolites of chlorinated organophosphorous flame retardants (OPFRs: bis(2-chloroethyl) phosphate, bis(chloropropyl) phosphate and bis(1,3-dichloro-2-propyl) phosphate) in wastewater. A solid-phase extraction procedure based on the use of mixed-mode reversed-phase weak anion exchange sorbents was optimized including a fractionated elution of OPFRs and their metabolites. Analytes derivatization was investigated by comparing two silylating reagents, N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide and N-methyl-N-(trimethylsilyl)trifluoroacetamide, the first one providing better results. Determination was performed by gas chromatography-high resolution mass spectrometry with a quadrupole-time-of-flight system (GC-QTOF) in order to improve selectivity. Furthermore, the use of GC-QTOF combined with the specific ion obtained from silylated metabolites (m/z 154.9924) can be exploited to screen for other phosphate ester metabolites. Under final conditions, the overall method performance was satisfactory, affording method detection limits ranging from 1.1 to 4.6 ng/L, percentages of recovery from 90% to 110%, and relative standard deviations below 13%. The analysis of composite raw wastewater samples collected over 24 h in the NW of Spain allowed to quantify, for the first time in this matrix, the metabolite bis(chloropropyl) phosphate at levels over 60 ng/Leng© 2019 Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0 license (http://creativecommons.org/licenses/by-nc-nd/4.0/)http://creativecommons.org/licenses/by-nc-nd/4.0/Phosphorous flame retardants and plasticizersMetabolitesWastewaterHuman exposureSilylationGas chromatography-high resolution mass spectrometryjournal article10.1016/j.chroma.2019.06.015open access